After this date, new performance standards will apply to Openreach, the company that installs and maintains connections to BT's network on behalf of competing providers.

Under the changes, at least 70% of phone and broadband faults will have to be repaired within two working days, and at least 55% of customers requiring a new line must receive an appointment within 12 working days. Both of these figures will rise to around 80% by 2016.

"Should Openreach fail to meet the new targets, the company will face sanctions from Ofcom, which could include fines," the watchdog warned.

Going forward, Openreach will also have to publicly report on its performance, publishing quarterly reports on its website from October at the latest, which Ofcom says must provide, "clear, meaningful and transparent information" about how long Openreach is taking to repair faults and install new lines.

It will also have to provide clear timeframes concerning how long current repairs or installations will take, in order to "provide reassurance to consumers", Ofcom says.

The new regulations are part of Ofcom's Fixed Access Market Reviews, which were unveiled in May and sent to the European Commission for review.

As part of these reviews, Ofcom also wants to make it cheaper for customers to change their superfast broadband provider.

At the moment, the current operator for of any customers looking change superfast broadband provider has to pay a £50 fee to Openreach, which often ends up being passed on to the consumer. Ofcom wants to cut this to £11, meaning providers would be able to offer lower set-up fees.

Users could also be offered shorter retail contracts as a result of the changes, as wholesale contracts between BT and suppliers will be cut from a year to one month.